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Path: utzoo!linus!decvax!ittvax!ittral!shacklet
From: shacklet@ittral.UUCP (Cliff Shackelton)
Newsgroups: net.followup
Subject: Re: TV Interference with Cordless Phone
Message-ID: <307@ittral.UUCP>
Date: Tue, 27-Sep-83 10:46:04 EDT
Article-I.D.: ittral.307
Posted: Tue Sep 27 10:46:04 1983
Date-Received: Wed, 28-Sep-83 08:57:58 EDT
References: <246@ihuxj.UUCP> houxz.519
Lines: 18

The present crop of cordless phones use the AC line for transmitting the voiceath to the handset at a frequency of around 1.7 Mhz. If the output of
the RF driver is not tuned properly, or some heavily inductive item
is on the same circuit ALL KINDS of crazy harmonics are produced. The kicker
is that the FCC doesn't specify a particular amount of power that can be
applied to th AC line but only a field stregnth at 3 meters from an 
arbitrary line. Most cordless phones pump in excess of !! 1 watt !! at
1.7 Mhz into the AC line. If you play around with the fine tuner on your
tv you can get the audio for the phone. BUT** don't fret! a tune up on your
phone by the factory or someone who knows what the're doing will cure
your problem. This reason is why th FCC is changing the requirement
for cordless phones to 49 & 46 Mhz at 100Mw power input, and may require
some sort of voice scrambling and line access security. Look for the new
wave of cordless phones from all manufacturers after next june that will
have these features.


		Cliff (I know we makem) Shackelton
		ITT Telecom